You need the same number on the bottom to add them (ie the pizza slice sizes have to be fair).The fastest way to do it at first is just times each top&bottom by the other ones bottom #. So it becomes(3*X/3*4) + (4*X/4*3). Do the timesing, then you can just run along and add the tops then bottoms.
It sounds like a stupid reply, but if you put the equation into google it goes through the process step by step giving both the instruction and the working.
You can express both factions as /12- if you multiply top and bottom by 3, x/4 becomes 3x/(3*4) or 3x/12, and x/3 is 4x/12. Adding together the factions of 12 you get 7x/12. Does that make sense as an explanation?
6ai x/4 + x/3=
First form a common denominator (the number below the line) by multiplying the first term by 3 and the second term by 4 to get
3 x/(4 * 3) + 4x/(3*4) =
Then simplify the denominator to get
3x/12 + 4x/12.
Then add terms on the numerator (the term above the line to get)
7x/12.
Comments
3x+4x=84
7x=84
X=12
x x 4 * x 3 * x
- + - = --- + ---
3 4 4 * 3 3 * 4
So then the denominators are both 12.
3*x + 4*x 7*x
= ---------- = ---
12 12
simplify x/4 + x/3
solve x/4 + x/3= 7
First form a common denominator (the number below the line) by multiplying the first term by 3 and the second term by 4 to get
3 x/(4 * 3) + 4x/(3*4) =
Then simplify the denominator to get
3x/12 + 4x/12.
Then add terms on the numerator (the term above the line to get)
7x/12.
3x/12 + 4x/12
Therefore
7x/12
To make the bottom the same, multiply 3x4
Then multiply x by each value below the line.
I *think*, it's been a long time!
To quote the Thousand Nights, "if it were written in the corner of your eye with a needle, would yet teach you wisdom"!